基于热动力学的磷酸镁水泥基材料水化性能及其调控机制研究

Magnesium phosphate cement (MPC), with high early strength, good durability and low porosity, have been thus widely used as concrete repair materials, etc. However, its short setting time and high reaction heat leads to difficult formation and then performance degradation of MPC. The reason of short setting time was found that the early hydration rate of MPC is very fast. Hence, in order to efficient utilization of MPC, through the research on hydration thermokinetics of MPC by using calorimeter, the factors on hydration rate of MPC will be discussed and hydration kinetics characteristics are analyzed; and then the hydration properties of MPC are discussed, and the relations between hydration rate and hydration properties of MPC should be stablished, on which combined with micro analysis using SEM, FT-IR ,NRM, TEM and MIA, etc, the modulation mechanism of hydration performance is clarified. The chievements of this work will not only promote the understanding of the nature of hydration reaction of MPC, but also contribute to comprehend the modulation measures and mechanism of hydration properties of MPC from the view of hydration kinetics, and be in favor of performance optimization and prediction.

磷酸镁水泥具有早期强度高、耐久性好、气孔率低等优点，因而可用作混凝土工程修补材料等应用。但其使用时存在凝结时间太短、水化放热量大的问题，造成成型困难，进而引发性能劣化。磷酸镁水泥基材料凝结时间短的根本原因在于其早期水化速率太快。因此，为了更有效地利用磷酸镁水泥基材料，本项目拟使用等温量热计测量其水化放热的热谱曲线，采用热动力学方法，研究水化反应速率的变化规律及影响因素，分析水化动力学特性；对磷酸镁水泥基材料水化性能进行分析，探寻水化速率与水化性能的内在联系；结合SEM、FT-IR、压汞仪、NRM、TEM等微观分析结果，进一步阐明调控磷酸镁水泥 水化性能的影响因素及其机制，并进行计算模拟材料内的热场分布及性能的模拟与预测。本项目的研究不仅可以从动力学角度认识磷酸镁水泥水化反应的本质，而且还有助于从水化动力学的层面来分析调控磷酸镁水泥水化性能的措施及性能优化与预测。

磷酸镁水泥具有早期强度高、耐久性好、气孔率低等优点，因而可用作混凝土工程修补材料等应用。但其使用时存在凝结时间太短、水化放热量大的问题，造成成型困难，进而引发性能劣化。磷酸镁水泥基材料凝结时间短的根本原因在于其早期水化速率太快。因此，为了更有效地利用磷酸镁水泥基材料，本项目利用等温量热仪测量其水化放热的热谱曲线，采用热动力学方法，研究水化反应速率的变化规律及影响因素，分析水化动力学特性；对磷酸镁水泥基材料水化性能进行分析，探寻水化速率与水化性能的内在联系；结合SEM、EDS等微观分析结果，阐明磷酸镁水泥界面过渡区的结构。